From “study notes” found in the Bible online : Matthew 26:28
blood of the covenant: The new covenant, between Jehovah and anointed Christians, was made operative by Jesus’ sacrifice. (Heb 8:10) Jesus here uses the same expression Moses used when acting as mediator and inaugurating the Law covenant with Israel at Mount Sinai. (Ex 24:8; Heb 9:19-21) Just as the blood of bulls and goats validated the Law covenant between God and the nation of Israel, Jesus’ blood made valid the new covenant that Jehovah would make with spiritual Israel. That covenant went into effect at Pentecost 33 C.E.—Heb 9:14, 15.
This is the study notes on Luke 22:20: new covenant by virtue of my blood: Luke is the only Gospel writer to record that Jesus on this occasion referred to a “new covenant,” an allusion to Jer 31:31. The new covenant, between Jehovah and anointed Christians, was made operative by Jesus’ sacrifice. (Heb 8:10) Jesus here uses the terms “covenant” and “blood” in a way similar to the way Moses used the terms when acting as mediator and inaugurating the Law covenant with Israel at Mount Sinai. (Ex 24:8; Heb 9:19-21) Just as the blood of bulls and goats validated the Law covenant between God and the nation of Israel, Jesus’ blood made valid the new covenant that Jehovah would make with spiritual Israel. That covenant went into effect at Pentecost 33 C.E.—Heb 9:14, 15.
. . . poured out in your behalf: The words from the middle of verse 19 (“which is to be given . . .”) to the end of verse 20 are missing in some manuscripts, but this passage has strong support in early authoritative manuscripts.—For more information about how ancient manuscripts are used to establish the Greek text, see App. A3.
See how the study notes on the sighted scriptures show the new covenant to be about the anointed or spiritual Israel rather than what Jesus himself said...it is for forgiveness of sin.